Search results for "Photon"
showing 10 items of 3171 documents
Experimental generation of parabolic pulses via Raman amplification in optical fiber
2003
Parabolic pulse generation via Raman amplification is experimentally demonstrated in 5.3 km of non-zero dispersion shifted fiber presenting normal group velocity dispersion at the injected signal pulse wavelength of 1550 nm. The fiber is pumped by a commercially-available continuous wave source at 1455 nm, and the intensity and chirp of the amplifier output are characterized using frequency-resolved optical gating. For 2.4 pJ input pulses of 10 ps duration, the output pulse characteristics are studied as a function of amplifier gain over the range 11-24 dB, allowing the evolution of the input pulse to a parabolic pulse to be clearly seen for amplifier gains exceeding 15 dB. Numerical compre…
All-fibered high-quality low duty-cycle 20-GHz and 40-GHz picosecond pulse sources
2007
International audience; In this work, we demonstrate all-fibered 20-GHz and 40-GHz picosecond pulse sources with duty cycles as low as 1/14. The pulse train is achieved via the high-quality compression of an initial sinusoidal beating through four segments of optical fibers. General design rules are proposed and experimental results are in agreement with numerical predictions.
Impact of initial pulse shape on the nonlinear spectral compression in optical fibre
2018
International audience; We theoretically study the effects of the temporal intensity profile of the initial pulse on the nonlinear spectral compression process arising from nonlinear propagation in an optical fibre. Various linearly chirped input pulse profiles are considered, and their dynamics is explained with the aid of time-frequency representations. While initially parabolic-shaped pulses show enhanced spectral compression compared to Gaussian pulses, no significant spectral narrowing occurs when initially super-Gaussian pulses are used. Triangular pulses lead to a spectral interference phenomenon similar to the Fresnel bi-prism experiment.
Femtosecond parabolic pulse shaping in normally dispersive optical fibers
2013
Formation of parabolic pulses at femtosecond time scale by means of passive nonlinear reshaping in normally dispersive optical fibers is analyzed. Two approaches are examined and compared: the parabolic waveform formation in transient propagation regime and parabolic waveform formation in the steady-state propagation regime. It is found that both approaches could produce parabolic pulses as short as few hundred femtoseconds applying commercially available fibers, specially designed all-normal dispersion photonic crystal fiber and modern femtosecond lasers for pumping. The ranges of parameters providing parabolic pulse formation at the femtosecond time scale are found depending on the initia…
All-fiber spectral compression of picosecond pulses at telecommunication wavelength enhanced by amplitude shaping
2012
International audience; We demonstrate efficient spectral compression of picosecond pulses in an all-fiber configuration at telecommunication wavelengths. A spectral compression by a factor 12 is achieved. Performing temporal shaping with a parabolic pulse significantly improves the spectral compression with much lower substructures and an enhanced Strehl ratio.
Experimental properties of parabolic pulses generated via Raman amplification in standard optical fibers
2004
Parabolic pulses at 1550 nm have been generated in a standard telecommunications fiber using Raman amplification. The parabolic output pulse characteristics are studied as a function of input pulse energy and duration.
Ultra-flat SPM-broadened spectra in a highly nonlinear fiber using parabolic pulses formed in a fiber Bragg grating
2006
International audience; We propose a new method for generating flat self-phase modulation (SPM)-broadened spectra based on seeding a highly nonlinear fiber (HNLF) with chirp-free parabolic pulses generated using linear pulse shaping in a superstructured fiber Bragg grating (SSFBG). We show that the use of grating reshaped parabolic pulses allows substantially better performance in terms of the extent of SPM-based spectral broadening and flatness relative to conventional hyperbolic secant (sech) pulses. We demonstrate both numerically and experimentally the generation of SPMbroadened pulses centred at 1542nm with 92% of the pulse energy remaining within the 29nm 3dB spectral bandwidth. Appli…
Supercontinuum generation at 800 nm in all-normal dispersion photonic crystal fiber
2014
We have numerically investigated the supercontinuum generation and pulse compression in a specially designed all-normal dispersion photonic crystal fiber with a flat-top dispersion curve, pumped by typical pulses from state of the art Ti:Sapphire lasers at 800 nm. The optimal combination of pump pulse parameters for a given fiber was found, which provides a wide octave-spanning spectrum with superb spectral flatness (a drop in spectral intensity of ~1.7 dB). With regard to the pulse compression for these spectra, multiple-cycle pulses (~8 fs) can be obtained with the use of a simple quadratic compressor and nearly single-cycle pulses (3.3 fs) can be obtained with the application of full pha…
Ultra-short pulse propagation in birefringent fibers—the projection operator method
2008
We examine the propagation of ultra-short optical light pulses in dispersion-managed birefringent fiber transmission systems, in which the pulse dynamics is governed by the coupled higher-order nonlinear Schrodinger equations with higher-order linear and nonlinear optical effects. We derive the equations of motion in terms of pulse parameters such as amplitude, temporal position, width, chirp, frequency and phase, using a projection operator method, and we obtain the spatial dynamical behavior of picosecond and femtosecond pulse parameters. From our detailed analysis, we show that the stimulated Raman scattering has a strong impact on the pulse dynamics.
Parabolic Pulse Amplifiers
2008
International audience; Recent studies in nonlinear optics have led to the discovery of a new class of ultrashort pulse generated in fiber amplifiers by the self-similar propagation of an arbitrary input pulse. These pulses with a parabolic shape and linear chirp, called `optical similaritons,' represent asymptotic solutions of the nonlinear Schrödinger equation with gain, towards which any initial pulse of given energy converges, independently of its intensity profile. Parabolic pulse amplifiers can be easily developed with standard optical fibers and commercial devices. Our goal here is to emphasize the main properties of similaritons and to discuss a few of their numerous new application…